Methods for splicing optical fibers using an optical fiber repair apparatus with adjustable guide member

ABSTRACT

Methods for splicing optical fibers include coupling a first optical fiber cable to a longitudinally extending closure frame and coupling a second optical fiber cable to an adjustable guide member on the closure frame. The adjustable guide member is moved toward the first optical fiber cable to provide a distance between the first and second optical fiber cable less than an exposed length of the first and second optical fiber therebetween to provide a slack length of optical fiber. Cleaved exposed ends of a first optical fiber from the first optical fiber cable and a second optical fiber from the second optical fiber cable are positioned proximate each other in a splice station displaced from the closure frame utilizing the slack length of optical fiber. The first and second optical fibers are spliced in the splice station and the adjustable guide member is moved away the first optical fiber cable to remove the slack length and position the spliced optical fibers in the closure frame

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.11/106,242, filed Apr. 14, 2005, the content of which is hereinincorporated by reference in its entirety as if set forth fully herein.

BACKGROUND OF THE INVENTION

The present invention relates to communication cable termination devicesand, more particularly, to optical fiber repair apparatus and methodsfor using the same.

An extensive infrastructure supporting telecommunication has beendeveloped, traditionally based upon copper wire connections betweenindividual subscribers and telecommunications company networkdistribution points. More recently, much of the telecommunicationsnetwork infrastructure is being extended or replaced with an opticalfiber based communications network infrastructure. Fiber optic cablesare widely used for telecommunications applications where highinformation capacity, noise immunity and other advantages of opticalfibers may be exploited. Fiber cable architectures are emerging forconnecting homes and/or business establishments, via optical fibers, toa central location, for example.

A typical main fiber optic cable may be installed underground and havemultiple drop cables connected thereto, each of a hundred feet or more.Each of the drop cables, in turn, is routed to an optical network unit(ONU) serving several homes. Accordingly, information may be transmittedoptically to the ONU, and into the home via conventional copper cabletechnology. Thus, the drop cables may serve groups of users, althoughother architectures may also employ a main cable and one or more dropcables connected thereto.

Unfortunately, the fibers within the main cable must typically beaccessed at the various drop points and spliced to respective dropcables after the main cable has already been installed. Accessing themain cable for splicing generally requires careful preparation of themain cable including removing a portion of the cable sheath, andidentifying and separating out predetermined fibers from within thecable without disturbing adjacent fibers. The separated fibers may thenbe spliced and secured within a conventional protective splice closure.Moreover, these cable access and splicing steps must typically beaccomplished in the field by a technician who is likely to experiencedifficulties imposed by weather or the particular location of each ofthe drop points. Accordingly, field splicing of drop cables to a maincable may be time consuming, expensive, and may produce low qualityoptical splices.

In addition to drop point termination splicing operations, the installedoptical fiber cables may be subject to damage over time. For example, adrop cable could be inadvertently cut with a resulting loss of serviceover the optical fibers therein. Rather than replace the cablinginfrastructure to repair the damage, the cut drop cable may be repairedby cleaving and splicing the severed ends of the optical fibers in thedrop cable. However, in addition to the problems discussed above withdrop point termination splicing operations, difficulties may beencountered in physically connecting ends of a cut optical fiber basedon available length of fiber on each end and limitations on the abilityto move the respective ends into an adjacent position for splicing andthen to return the repaired cable into use without damaging the opticalfiber(s).

SUMMARY OF THE INVENTION

Embodiments of the present invention include optical fiber repairapparatus including a longitudinally extending closure frame having alongitudinally extending optical fiber receiving groove in a facethereof. An adjustable guide member on the closure frame islongitudinally movable thereon to adjust a position of an optical fiberof a first optical fiber cable in the groove. A first attachment memberis configured to couple the first optical fiber cable to the guidemember with the optical fiber of the first optical fiber cable extendinginto the optical fiber receiving groove. A retainer is configured tocouple a second optical fiber cable to the closure frame with an opticalfiber of the second optical fiber cable extending into the optical fiberreceiving groove.

In other embodiments of the present invention, the adjustable guidemember is configured to direct the optical fiber of the first opticalfiber cable into the groove. The retainer may be configured to directthe optical fiber of the second optical fiber cable into the groove. Theretainer may be a second adjustable guide member configured to directthe optical fiber of the second optical fiber cable into the groove andhaving a second attachment member configured to couple the secondoptical fiber cable to the second adjustable guide member. The opticalfiber of the first optical fiber cable may be positioned in an opticalfiber tube and the adjustable guide member may be configured to directthe optical fiber tube into the groove.

In further embodiments of the present invention, the adjustable guidemember is a slide member having an opening therein configured toslidably engage an outer surface of the closure frame and the opticalfiber tube is received into the opening and directed to the groove bycontact with the slide member in the opening. The opening may include arotary limit portion configured to contact a rotary limit portion of theclosure frame to limit rotational movement of the guide member about theclosure frame.

In other embodiments of the present invention, the first optical fibercable further includes a strength member and the attachment member isconfigured to connect the strength member to the guide member. The guidemember may include a strength member receiving opening thereinconfigured to receive the strength member for attachment therein and thestrength member receiving opening may be positioned to provide anangular displacement between the strength member and the optical fibertube extending from the first optical fiber cable to force the opticalfiber tube against the guide member in the opening in the guide memberand direct the optical fiber tube into the groove.

In yet other embodiments, the first optical fiber includes two strengthmembers extending therein on opposite sides of the optical fiber tubeand the guide member includes two strength member receiving openingstherein positioned above the closure frame and the opening in the guidemember and on opposite sides of the groove. The closure frame mayfurther include a longitudinally extending guide channel configured toreceive a flat drop cable and/or longitudinally extending contactsurfaces configured to receive a round drop cable. The contact surfacesmay include edges of the groove.

In further embodiments of the present invention, a splice cover isprovided that is configured to be positioned on the closure frame overthe groove. An outer closure may be positioned around and enclosing theclosure frame to provide environmental sealing for a cable splicetherein and/or strain relief for the first and second optical fibercables extending therein. The outer closure may be, for example, aheatshrink and/or cold seal outer closure.

In yet further embodiments of the present invention, a cable fixture isprovided that is configured to receive and retain the closure frame at aposition proximate a splice device. The cable fixture may include acable frame configured to receive the closure frame, a first retentionmember configured to retain the first optical fiber cable and a secondretention member configured to retain the second optical fiber cable.

In other embodiments of the present invention, methods for splicingoptical fibers include coupling a first optical fiber cable to alongitudinally extending closure frame. A second optical fiber cable iscoupled to an adjustable guide member on the closure frame. Theadjustable guide member is moved toward the first optical fiber cable toprovide a distance between the first and second optical fiber cable lessthan an exposed length of the first and second optical fibertherebetween to provide a slack length of optical fiber. Cleaved exposedends of a first optical fiber from the first optical fiber cable and asecond optical fiber from the second optical fiber cable are positionedproximate each other in a splice station displaced from the closureframe utilizing the slack length of optical fiber. The first and secondoptical fibers are spliced in the splice station and the adjustableguide member is then moved away the first optical fiber cable to removethe slack length and position the spliced optical fibers in the closureframe.

In further embodiments of the present invention, positioning exposedcleaved ends is preceded by exposing a length of the first opticalfiber, exposing a length of the second optical fiber and cleavingrespective exposed ends of the first and second optical fiber. Movingthe adjustable guide member may be followed by securing the adjustableguide member to the closure frame in a position where the splicedoptical fibers therein have the slack length removed and environmentallysealing the closure frame with the spliced optical fibers therein.Environmentally sealing may be preceded by placing a cover on theclosure frame with the spliced optical fibers therein andenvironmentally sealing may include securing a heatshrink and/or coldseal outer closure around the closure frame. Moving the adjustable guidemember may be preceded by coupling a cable fixture to a splice apparatusincluding the splice station and coupling the closure frame to the cablefixture.

In yet other embodiments of the present invention, the method includesrepairing a broken fiber drop cable where the break defines a firstexposed end and a second exposed end of a broken optical fiber therein.The first exposed end is an exposed end of the first optical fibercable. The second optical fiber cable is a bridging optical fiber cablewith an opposite cleaved end of the second optical fiber extending fromthe bridging optical fiber. The opposite cleaved end of the secondoptical fiber is spliced to the second exposed end of the broken opticalfiber cable using a second closure frame.

In further embodiments of the present invention, the first optical fiberis a first plurality of optical fibers and the second optical fiber is asecond plurality of optical fibers. Splicing the first and secondoptical fibers includes splicing respective ones of the first and secondplurality of optical fibers. Splicing the first and second opticalfibers may be followed by positioning a protective sleeve over thesplice and moving the adjustable guide member may include positioningthe protective sleeve in the closure frame. The second optical fibercable may include a strength member and coupling the second opticalfiber cable to an adjustable guide member may include connecting thestrength member to the adjustable guide member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view illustrating an optical fiber repairapparatus according to some embodiments of the present invention;

FIG. 1B is a perspective view illustrating an optical fiber repairapparatus according to some embodiments of the present invention;

FIG. 2 is an exploded perspective view of the apparatus of FIG. 1A;

FIG. 3 is a side view of an adjustable guide member having a drop cablecoupled thereto according to some embodiments of the present invention;

FIG. 4 is a perspective view of an adjustable guide member having a dropcable coupled thereto according to some embodiments of the presentinvention;

FIG. 5 is a side view of a closure frame with an adjustable guide memberwith a drop cable thereon according to some embodiments of the presentinvention;

FIG. 6 is a side view of a closure frame with an adjustable guide memberwith a drop cable thereon according to further embodiments of thepresent invention;

FIG. 7 is a perspective view of a closure frame and outer closureaccording to some embodiments of the present invention;

FIG. 8 is a perspective view of a closure frame and outer closureaccording to further embodiments of the present invention;

FIG. 9 is a flowchart illustrating operations for splicing an opticalfiber according to some embodiments of the present invention; and

FIG. 10 is a flowchart illustrating operations for splicing an opticalfiber according to further embodiments of the present invention.

DETAILED DESCRIPTION

The present invention now will be described more fully hereinafter withreference to the accompanying drawings, in which illustrativeembodiments of the invention are shown. In the drawings, the relativesizes of regions or features may be exaggerated for clarity. Thisinvention may, however, be embodied in many different forms and shouldnot be construed as limited to the embodiments set forth herein; rather,these embodiments are provided so that this disclosure will be thoroughand complete, and will fully convey the scope of the invention to thoseskilled in the art.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, components, regions, layersand/or sections, these elements, components, regions, layers and/orsections should not be limited by these terms. These terms are only usedto distinguish one element, component, region, layer or section fromanother region, layer or section. Thus, a first element, component,region, layer or section discussed below could be termed a secondelement, component, region, layer or section without departing from theteachings of the present invention.

Spatially relative terms, such as “beneath”, “below”, “lower”, “above”,“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the exemplary term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Embodiments of the present invention will now be described withreference to the various embodiments illustrated in FIGS. 1A-8.Referring first to FIGS. 1A and 2, the optical fiber repair apparatus100 according to some embodiments of the present invention provides forsplicing of an optical fiber 125 a in a first optical fiber cable 120 ato a second optical fiber 125 b in a second optical fiber cable 120 b.For example, the first and second optical fiber cables 120 a, 120 b maybe respective ends of a broken optical fiber drop cable to bere-connected using the apparatus 100. As would readily be understood bythose skilled in the art, a drop cable is typically a low fiber countcable, such as 2 or 4 fibers, while a main cable typically includes alarger number of optical fibers. As also shown in FIG. 1A, the opticalfibers 125 a and 125 b may be within respective optical fiber tubes 130a, 130 b.

As will be described more fully below, various embodiments of opticalfiber repair apparatus and methods according to the present inventioncan be used in a fiber optic network, for example, to repair orre-connect fibers or cables. Such fiber, fiber cables and fiber splicescan be damaged, broken or become otherwise defective in the field. Invarious embodiments of the present invention, one or two closures may beused to re-establish the continuity of the fiber network. The closuremay be used for fusion splicing flat drop style fiber cable or othertype splices or cable types. The closure itself may be low profile and,in some embodiments, may be installed wherever repairs are neededwhether aerial, below grade or buried applications. The damaged sectionsof the cable can either be removed and replaced using two repairclosures, one at each end, or be re-established in some embodimentsusing a single closure. The selection of the approach to use for repairmay be based on a consideration of how much free cable length isavailable at the location of the break or damaged section of cable todetermine if a bridging cable is needed between the broken ends.

It will generally be understood that in order to re-splice a givensection of fiber cable, the fiber must generally first be prepared. Forexample, for a section of flat drop sheath cable, approximately 7 inchesmay be removed of the sheath from the end of the cable. This may beaccomplished, for example, by making a ring cut and removing the jacketfrom this length. The cable may include a loose buffer tube (LBT) andthe loose buffer tube may also be removed to within an inch or so of thering cut leaving about 6 inches of bare fiber or fibers.

The optical fiber cable 120 a, 120 b may be connected to the retainer135 or guide member 115 after removing a portion of the sheath from thedrop cable and after removing a length of the exposed loose buffer tube.The connection to the retainer 135 or guide member 115 in otherembodiments of the present invention may be between removing of thesheath and removing of an exposed portion of the loose buffer tube. Byremoving the loose buffer tube after attaching the retainer 135 or guidemember 115, the loose buffer tube may provide further protection to theoptical fiber itself during the attachment operations.

It is generally important to accurately cleave fibers before splicing.Cleaving a fiber will shorten the available fiber length and the ends ofthe original fiber are generally discarded, exposing the new cleavedfiber ends. These cleaved fiber ends can then be spliced together togenerally provide reliable connections. Cleaving fibers typicallyreduces the fiber length available by approximately 0.5 inch.

As shown in the embodiments of FIGS. 1A and 2, the optical fiber repairapparatus 100 includes a longitudinally extending closure frame 105 witha longitudinally extending optical fiber receiving groove 110 in anupper face thereof. An adjustable guide member 115, 115′ is positionedon the closure frame 105 so as to be longitudinally moveable on theclosure frame 105. The adjustable guide member 115, as will be furtherdescribed herein, may be used to adjust the position of an optical fiber125 a of a first optical fiber cable 120 a in the groove 110 andrelative to the optical fiber 125 b and cable 120 b so that the opticalfibers 125 a, 125 b can be moved into a splicing apparatus 180 forrepair and then returned into the groove 110 of the closure member 105without any slack coils of optical fiber therein.

Also shown in FIGS. 1A and 2 is a first attachment member 140 in theadjustable guide member 115 that is configured to couple the firstoptical fiber cable 120 a to the adjustable guide member 115 with theoptical fiber 125 a and tube 130 a extending into the optical fiberreceiving groove 110. More particularly, the first attachment member 140shown in the embodiments of FIG. 1A and 2 is a pair of set screws 140 aswill be described further herein.

Also shown in the embodiments of FIGS. 1A and 2 is a retainer 135configured to couple the second optical fiber cable 120 b to the closureframe 105 with the optical fiber 125 b and tube 130 b of the secondoptical fiber cable 120 b extending into the optical fiber receivinggroove 110. The retainer 135 shown in the illustrated embodimentsincludes an attachment member 145 to attach the second optical fibercable 120 b to the retainer 135, shown as a pair of set screws 145 inthe illustrated embodiments of FIGS. 1A and 2. As will be describedfurther herein, the set screws 140, 145 may be utilized to attachstrength members extending from the respective optical fiber cables 120a, 120 b to the guide member 115 and the retainer 135.

As illustrated in the embodiments of FIG. 1B, an adjustable guide member115 a may be used in place of the retainer 135. Thus, for theembodiments illustrated in FIG. 1B, a slack length of optical fiber maybe provided by both guide members 115, 115 a. Furthermore, it will beunderstood that the general configuration of the retainer 135 may itselfbe configured to be longitudinally moveable on the closure frame 105 andboth the retainer and adjustable guide member may be configured in amanner illustrated for the retainer 135 in FIGS. 1A and 2.

As shown in the embodiments of FIGS. 1A and 2, the adjustable guidemember 115 has an opening 150 therein that is configured to slidablyengage an outer surface 105 a of the closing member 105. Thus, theadjustable guide member 115 may move from a position 115 to a position115′, as illustrated in dotted line in FIG. 1, by being slidlongitudinally along the closure frame 105.

Also shown in the embodiments of the FIGS. 1A and 2 is a cable fixture160 configured to receive and retain the closure frame 105 at a positionproximate a splice device 180. A first retention member 165 configuredto retain the first optical fiber cable 120 a connected to the cablefixture 160 is also shown in FIGS. 1 and 2. The retention member 165includes a bracket 167 for connecting the retention member 165 to thecable fixture 160 and a contact pad 168 for clamping the closure frame105 and/or adjustable guide member 115 in a desired longitudinalposition on the cable fixture 160. A lever 169 is used to activatemovement of the retention member 165 to move the compression member 168to open and closed positions thereof. The compression member 168, insome embodiments of the present invention, is a compliant material thatmay reduce the risk of damage to the adjustable guide member 115 orclosure member 105 due to variability in the parts when clamping aclosure frame 105 to the cable fixture 160. Also seen in the embodimentsin FIGS. 1A and 2 is a second retention member 170, that, similarly tothe first retention member 165 includes an activating lever 174, abracket 172, and a compression member 173 for securing and retaining thesecond optical fiber cable 120 b in position relative to the cablefixture 160.

As best seen in FIG. 2, the splice apparatus 180 may include a cover 181rotatably attached to the splice apparatus 180 by a hinge 183. A splicestation 282 may be located under the cover 181 and be assessable byopening cover 181 so as to receive cleaved ends of the fibers 125 a and125 b for splicing the cleaved ends together to repair the opticalfiber. Also shown in FIG. 2 is a heating station 284 that may be used,for example, to heat shrink a protective sleeve that may be slid overthe spliced ends of the optical fibers 125 a, 125 b to provideprotection and/or mechanical support to the newly spliced connections.

Additional aspects of the cable fixture 160, according to someembodiments of the present invention, are also visible in the explodeperspective view of FIG. 2. As shown in FIG. 2, respective channels 262and 263 are configured to receive the closure frame 105 therein. Alsoshown is a wider diameter channel portion 264 that has a diameterselected to allow movement of the adjustable guide member 115 into thechannel 264. Finally, a coupling region 261 of the closure fixture 160may be configured to mate with corresponding features of the splicedevice 180 to facilitate positioning of the cable fixture 160 proximatethe splice device 180. Further details of the retainer 135 are alsoshown and will be further described with reference to FIG. 2.

As seen in FIG. 2, the retainer 135 may include longitudinally extendingfinger members 237 passing over the optical fiber cable 120 b with anattachment member 236, such a tie wrap or the like, wrapped around thefingers 237. Where it is desired to utilize the retainer 135 as anadjustable guide member, curved portions 239 of the retainer 135 may beconfigured to slidably engage the outer surface 105 a of the closureframe 105 for longitudinal movement along the closure frame 105. Theattachment member 236 may be pre-compressed to provide a connectionbetween the retainer 135 and the cable 120 b while continuing allowingslideable movement of the retainer 135 along the closure member 105 ormay be compressed with the closure frame 105 therein to provide furthermechanical attachment to the closure frame 105 rather than to theoptical fiber cable 120 b.

As noted previously, the optical fiber cable 120 b may be attached tothe retainer 135 using the set screws 140. More particularly, a pair ofstrength members extending from the cable 120 b may be inserted upagainst respective stop arms 238 of the retainer 135 and then the setscrews 140 may be tightened thereon to retain the strength members and,thereby, the optical fiber cable 120 b coupled to the retainer 135.

The relationship between the adjustable guide member 115 and opticalfiber cable 120, 120 b will now be further described for someembodiments of the present invention with reference to FIGS. 3 and 4. Asseen in FIG. 3, an adjustable guide member 415 includes an attachmentmember, more particularly, a pair of set screws 440, associated withcorresponding strength member receiving openings 454 in the guide member415 positioned above the opening 450 in the guide member 415 and onopposite sides of the center line of the guide member 415. The openings454 receive respective strength members 452 therein extending from theoptical fiber cable 420 a and the set screws 450 may be tightenedagainst the strength members 452 to attach the strength members 452 inthe openings 454. As seen in FIG. 3, the positioning of the openings 452provides an angular displacement between the strength members 452 and anoptical fiber tube 430 extending from the optical fiber cable 420 a toforce the optical fiber tube 430, with the optical fiber 425 therein,against the guide member 415 in the opening 450 in the guide member 415so as to direct the optical fiber tube 430 and optical fiber 425 intothe groove 110.

As seen in the perspective view illustration of FIG. 4, the strengthmembers 452 extend on opposite sides of the optical fiber tube 430 inthe optical fiber drop cable 420. As also seen in FIG. 4, the set screws440 extend through threaded openings 441 in the guide member 415.Similarly the set screw 458 extends through a threaded opening 459 inthe guide member 415 to allow the guide member 415 to be secured to theclosure frame 105 at desired longitudinal position.

The guide member 415 is illustrated in FIG. 5 with a closure frame 505extending through the opening 450. As further illustrated in FIG. 5, theoptical fiber tube 430 contacts the inner surface of the opening 450 inthe guide member 415 to direct the optical fiber tube 430 and opticalfiber 420 into a groove 510 in a face of the closure frame 505. Moreparticularly, the strength member receiving openings 454 are positionedto provide an angular displacement between the strength members 452 andthe optical fiber tube 430 extending from the optical fiber cable fiber420 so as to force the optical fiber tube 430 against the guide member415 in the opening 450 to direct the optical fiber tube 430 and opticalfiber 420 into the groove 510. The embodiments in FIG. 5 further show aguide channel 556 configured to receive the flat drop cable 420 therein.

FIG. 6 illustrates further embodiments of the present invention. Theembodiments illustrated in FIG. 6 are shown with a round drop cable 620rather than a flat drop cable 420 as described with reference to FIG. 5.The round drop cable 620 has an optical fiber tube 630 extending thereinwith an optical fiber 625 within the optical fiber tube 630. Inaddition, a pair of strength members 652 are positioned on respectivesides of the optical fiber tube 630 substantially as describedpreviously with reference to the strength members 452 of the flat dropcable 420. The guide member 615 includes strength member receivingopenings 654 and attachment set screws 640 associated with each opening654 for securing the strength members 652 within the respective openings654 as was described previously with reference to the openings 454 andset screws 440.

The embodiments of FIG. 6 differ from those described with reference toFIG. 5 in the inclusion in the opening 650 of a rotary limit portion651, shown as a flat faced portion as contrasted with the circularconfiguration of the opening 450 of the embodiments of FIG. 5. Therotary limit portion 651 of the opening 650 is configured to contact arotary limit portion 613 of the closure frame 605. The rotary limitportion 651 of the guide member 615 is thereby configured to limitrotational movement of the guide member 615 about the closure member605.

The closure frame 605 further differs from the closure frame 505described with reference to FIG. 5 in the configuration of the receivingportions thereof for receiving the optical fiber cable 620, the opticalfiber tube 630 and the optical fiber 615. In particular, the closureframe 605 includes longitudinally extending contact surfaces 612configured to receive the round drop cable 620. As illustrated in FIG.6, the contact surfaces 612 include edges of a groove 610 configured toreceive the optical fiber tube 630 and optical fiber 625.

Further embodiments of the guide member 615 are also shown in dottedline in FIG. 6. More particularly, in some embodiments of the presentinvention, both the outer circumferential shape of the guide member 615and the opening 650 have flattened portions. As shown in dotted line inFIG. 6, a flat portion 615 a may be provided at an angular locationcorresponding to the rotary limit portions 651, 613. The set screw 658′for securing the closure frame 605 may then be positioned in and extendthrough the flat portion 615 a of the guide member 615.

Further embodiments of the present invention will now be described withreference to FIG. 7. As shown in the embodiments of FIG. 7, a closuremember 105 may be provided with a splice cover 706 configured to bepositioned on the closure frame 105 over the groove 110. A pair of hoseclamps 707, as shown in the embodiments of FIG. 7, couple the splicecover 706 to the closure frame 105. In addition, tie wraps 708 are shownsecuring respective fiber optical cables 120 a, 120 b to the closureframe 105. An outer closure 790 is positioned around the closure frame105 with an environmental sealant 792, such as a silicon gel, on aninside surface thereof.

The hose clamps 707 may also be configured to retain the strengthmembers 452, 652 at a fixed longitudinal position and the tie wraps 708may hold the optical fiber drop cables 120 a, 120 b at a fixedlongitudinal position relative to the closure frame 105. Thus, thestrength members 452, 652 may be held in a fixed longitudinal positionrelative to the cables 120 a, 120 b, which may be beneficial when theouter closure 790 including the closure frame 105 is subjected tochanging temperature and other environmental conditions as the strengthmembers 452, 652 are typically of a material that is temperature stablewhile other components such as the optical fiber tube 430 may be subjectto dimension change with temperature. As shown in the embodiments ofFIG. 8, which will be described further below, in other embodiments ofthe present invention the outer closure 790, 890 itself may provide forfixing the longitudinal position of the strength members 452, 652relative to the drop cables 120 a, 120 b.

While hose clamps 707 are shown as retaining the strength members 452,652 in a desired longitudinal position in FIG. 7, it will be understoodthat, in other embodiments of the present invention, the hose clamps 707are not used. The retainer 135 or guide member 115 may be used in placeof the hose clamps 707 to retain the strength members in a desiredposition. The splice cover 706 may be connected to the closure frame 105by a snap fit or the like.

The spacing between the strength members 452 and optical fiber tube 430provided by the guide member 415 (see FIG. 4) may advantageously allowthe environmental sealant 792 to fill the area therebetween. As such,flow of water and the like into the closure 790 from inside the cable120, 420 when, for example, the sheath of the cable 120, 420 has beentorn, may be limited to prevented.

The closure 790 illustrated in the embodiments of FIG. 7 is a cold sealouter closure that is sealed around the closure frame 105 by wrappingaround the closure frame 105 and coupling to itself at longitudinallyextending edges of the closure 790 to provide environmental sealing fora cable splice positioned in the closure frame 105. The closure 790 may,in some embodiments, include additional securing wraps thereon that mayprovide strain relief for the optical fibers 120 a, 120 b extendingtherein. An alternative version of an outer closure 890 is shown in FIG.8. The outer closure 890 in the embodiments of FIG. 8 is a heat shrinkclosure.

Methods for splicing optical fibers according to various embodiments ofthe present invention will now be described with reference to the flowchart illustrations of FIGS. 9 and 10. Referring first to FIG. 9,operations begin with coupling of a cable fixture 160 to a spliceapparatus 180 including a splice station 282 (Block 900). The closureframe 105 is coupled to the cable fixture 160 (Block 905). However,while shown as preceding the cable splice operations in FIG. 9, it willbe understood that cable preparation and attachment of cables to theclosure frame may occur prior to the described operations of Block 905.

In some embodiments of the present invention, preparation of the opticalfibers for splicing includes exposing a length of the first opticalfiber and a length of the second optical fiber to be spliced (Block910). As illustrated in the embodiments of FIG. 9, guide members 415,615 are installed on respective cable ends, for example, as illustratedin FIG. 4 (Block 915). The guide members 415, 615, with the cablesattached thereto, are installed/secured onto the closure frame 105(Block 920). The ends of the cables are positioned using one (or both)of the guide members 415, 615 to provide slack for splicing (Block 925).Note that, as will be described with reference to FIG. 10, various ofthe operations, such as those of Blocks 915-925, may be incorporated aspart of the splice operations at Block 935.

Exposed ends of the respective first and second optical fiber arecleaved preparatory to splicing the cleaved ends (Block 930). The firstand second optical fibers may then be spliced using the closure framewith adjustable guide member described previously as will be furtherdescribed for various embodiments of the present invention withreference to FIG. 10 (Block 935).

The position of the adjustable guide member is re-adjusted and the guidemember is secured to the closure frame in a position where the splicedoptical fibers therein have any slack length removed (Block 940). Whereresults are not satisfactory and a re-splice is needed (Block 945),operations at Blocks 930-940 may be repeated.

As discussed above, repair of a drop cable optical fiber may, in someinstances, be provided by use of a single closure frame and splicewhile, in other embodiments, two different closure frames and splicesare utilized with an additional length of bridging cable providedextending therebetween, for example, when insufficient slack is left atthe damaged region to provide a splice effectively due to lengthlimitations. Accordingly, if an additional splice is needed to completethe repair, as when a re-splice is needed (Block 945), the operationsdescribed with reference to Blocks 930-940 may be repeated for anadditional splice. Thus, operations may be repeated at Block 945 where,for example, a break in a broken fiber drop cable defines a first andsecond exposed end of the broken optical fiber therein. A bridgingoptical fiber cable length may be utilized with cleaved ends extendingfrom both ends thereof that are spliced to cleaved ends of respectiveends of a broken optical fiber extending from the ends where the breakoccurred. First and second closure members can be utilized for therespective coupling of broken exposed ends of an optical fiber in anoptical fiber drop cable to respective ends of the broken optical fiber.It will also be understood that a broken optical fiber drop cable mayactually comprise a plurality of optical fibers that have been brokenand require splicing. In such instances, the splicing operations asdescribed at Blocks 930 through 940 may be repeated for respective onesof the optical fibers.

If no re-splice (or additional splice) is needed (Block 945), a splicecover 706 may be placed on the closure frame 105 with the splice opticalfibers therein (Block 950). The closure frame with the spliced opticalfibers therein may then be environmentally sealed (Block 955). Theenvironmental sealing may be, for example, securing a heat shrink and/orcold seal outer closure around the closure frame.

Operations relating to splicing of optical fibers will now be furtherdescribed with reference to the flow chart illustration of FIG. 10 forsome embodiments of the present invention. For the embodimentsillustrated in FIG. 10, operations begin at Block 1000 by coupling afirst optical fiber cable to a longitudinally extending closure frame. Asecond optical fiber cable is coupled to an adjustable guide member onthe closure frame (Block 1005). Attachment of the closure frame to thecable fixture, as described with reference to Block 905 of FIG. 9, mayoccur after coupling of the optical fiber cable at Block 1005 in someembodiments of the present invention. The adjustable guide member ismoved toward the first optical fiber cable to provide a distance betweenthe first and second optical cable less than exposed length of the firstand second optical fiber therebetween (Block 1010). In other words,operations at Block 1010 may be utilized to provide a slack length ofoptical fiber that may be needed to move the optical fibers to a splicestation and the like.

Cleaved exposed ends of a first optical fiber from the first opticalfiber cable and a second optical fiber from the second optical fibercable are positioned proximate each other in a splice station displacedfrom the closure frame, utilizing the slack length of optical fiber(Block 1015). The first and second optical fibers are spliced in thesplice station (Block 1020). The adjustable guide member is then movedaway from the first optical fiber cable to remove the slack length andposition the spliced optical fibers in the closure frame (Block 1025).

As described above for various embodiments of the present invention, acable fixture may be provided that can be temporarily attached to asplice machine and provide attachment points for a closure frame inclose proximity to the splice machine, which may be particularly helpfulfor in-line splicing. A closure frame for use in supporting the splicemay then be temporarily attached to the cable frame and provide dropcable attachment points that are longitudinally adjustable thereon. Theclosure frame may, thereby, provide a controlled way of re-positioningdrop cables. A fiber/splice groove may be included in the closure framethe contains the bare fiber and any splice protection sleeve positionedover splice point between the fibers. In addition, some embodiments ofthe present invention utilize a strength member anchor point thatsecures strength members to a guide member of the closure frame thatallows adjustable movement thereof. By utilizing the strength membersfor connecting the drop cables to the closure frame, mechanical strengthmay be provided to prevent or limit cable ingress or egress from thework station.

In some embodiments of the present invention, a splice covering may beprovided over the closure frame covering the groove and splice thereinfor further protection of the exposed fiber and an outer closure may beprovided to protect the rest of the assembly that may provide sealingthereof. The outer closure may or may not be re-enterable and mayprovide some level of strain relief to the cable. After the drop cablesare prepped and fibers are cleaved, the ends may be brought together andsecured to the closure frame utilizing the strength members of the cablefor securing. The ends of the fiber may be spliced and then the dropcables may be repositioned to eliminate any superfluous loops of fiber,which may provide a very slim splice closure. A splice cover may beinstalled and an outer closure may be wrapped or shrunken around thecompleted splice and splice closure frame. Accordingly, variousembodiments of the present invention may provide for improvements inrepairs or splicing connections for drop cables and the like in thefield or otherwise.

The foregoing is illustrative of the present invention and is not to beconstrued as limiting thereof. Although a few exemplary embodiments ofthis invention have been described, those skilled in the art willreadily appreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention as defined inthe claims. In the claims, means-plus-function clauses are intended tocover the structures described herein as performing the recited functionand not only structural equivalents but also equivalent structures.Therefore, it is to be understood that the foregoing is illustrative ofthe present invention and is not to be construed as limited to thespecific embodiments disclosed, and that modifications to the disclosedembodiments, as well as other embodiments, are intended to be includedwithin the scope of the appended claims. The invention is defined by thefollowing claims, with equivalents of the claims to be included therein.

1. A method for splicing optical fibers, the method comprising: couplinga first optical fiber cable to a longitudinally extending closure frame;coupling a second optical fiber cable to an adjustable guide member onthe closure frame; moving the adjustable guide member toward the firstoptical fiber cable to provide a distance between the first and secondoptical fiber cable less than an exposed length of the first and secondoptical fiber therebetween to provide a slack length of optical fiber;positioning cleaved exposed ends of a first optical fiber from the firstoptical fiber cable and a second optical fiber from the second opticalfiber cable proximate each other in a splice station displaced from theclosure frame utilizing the slack length of optical fiber; splicing thefirst and second optical fibers in the splice station; and moving theadjustable guide member away the first optical fiber cable to remove theslack length and position the spliced optical fibers in the closureframe.
 2. The method of claim 1 wherein positioning exposed cleaved endsis preceded by: exposing a length of the first optical fiber; exposing alength of the second optical fiber; and cleaving respective exposed endsof the first and second optical fiber.
 3. The method of claim 2 whereinmoving the adjustable guide member is followed by: securing theadjustable guide member to the closure frame in a position where thespliced optical fibers therein have the slack length removed; andenvironmentally sealing the closure frame with the spliced opticalfibers therein.
 4. The method of claim 3 wherein environmentally sealingis preceded by placing a cover on the closure frame with the splicedoptical fibers therein and wherein environmentally sealing comprisessecuring a heatshrink and/or cold seal outer closure around the closureframe.
 5. The method of claim 1 wherein moving the adjustable guidemember is preceded by: coupling a cable fixture to a splice apparatusincluding the splice station; and coupling the closure frame to thecable fixture.
 6. The method of claim 1 wherein the method comprisesrepairing a broken fiber drop cable where the break defines a firstexposed end and a second exposed end of a broken optical fiber thereinand wherein the first exposed end comprises an exposed end of the firstoptical fiber cable and wherein the second optical fiber cable comprisesa bridging optical fiber cable with an opposite cleaved end of thesecond optical fiber extending from the bridging optical fiber andwherein the opposite cleaved end of the second optical fiber is splicedto the second exposed end of the broken optical fiber cable using asecond closure frame.
 7. The method of claim 1 wherein the first opticalfiber comprises a first plurality of optical fibers and the secondoptical fiber comprises a second plurality of optical fibers and whereinsplicing the first and second optical fibers comprises splicingrespective ones of the first and second plurality of optical fibers. 8.The method of claim 1 wherein splicing the first and second opticalfibers is followed by positioning a protective sleeve over the spliceand wherein moving the adjustable guide member includes positioning theprotective sleeve in the closure frame.
 9. The method of claim 1 whereinthe second optical fiber cable includes a strength member and whereincoupling the second optical fiber cable to an adjustable guide membercomprises connecting the strength member to the adjustable guide member.